Electrical timing apparatus



Sept. 16, 1952 R. s. FEiGAL 2,611,011

ELECTRICAL TIMING APPARATUS Filed Feb. 26, 1949 INVENTOR.

RICHARD S. FEIGAL ATTORNEY Patented Sept. 16, 1952 nf-UNITED STATES PATENT OFFICE ELECTRICAL TIMING APPARATUS Richard S. Feigal, Minneapolis, Minn., assignor to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware Application February 26, 1949, Serial No. 78,593

13 Claims. 1

The present invention is concerned with a timin apparatus by which it is possible to obtain a plurality of timing intervals from a single timing apparatus. More particularly, the presentlinv'ention is concerned with an electronic control device for obtaining a plurality of timed periods by utilizing the electrical characteristics of an electron discharge device and-its associated electrical networks.

In the present day automatic controls, such as the controls utilized with fuel burners, it is often desired to render certain portions of the controlled apparatus operative before others in order to insure maximum safety in the operation of the controlled apparatus. Such an apparatus is shown in the copending application, Serial No." 78,592, of John M. Wilson and Richard S. Feigal, filed on February 26, 194:9. With the apparatus of the present invention it is desired to obtain a first and a second timing interval following the closing of a main control switch and further timing interval following the opening of the main control switch.

The timing in the present invention is accomplished' by using the heating time of an indirectly heated cathode of an electron discharge device for obtaining a first timing interval; A further timing period is obtained following the first timing period by utilizing a resistor and condenser network having a predetermined discharge timing. A third timing interval is obtained by utilizing the cooling time of the indirectly'heated cathode of the associated discharge devices.

It is therefore an object of the present invention to provide a timing apparatus for obtaining a first timing interval following energization of an indirectly heated cathode of an electron discharge device and utilizing the cooling time of this cathode and the discharging of an associatedcondenser for obtaining a further timed inter-val.

Another object of the present invention is to provide an improved timing apparatus which utilizes delay in'thermionic emission for obtaining a first timed interval, which utilizes a resistor-condenser network for obtaining a second timed interval which is proportional to the thermionic emission and a third timed interval dependent upon the time it takes for the thermionic emission to die out.

Still another object of the present invention is'to provide a thermal electron emissive timer adapted to be energized to give a first timing interval following the energization thereof and to provide therewith a second timing means which 2 is energized a timed period following said firs time interval.

A still further object of the present invention is to provide in an electronic timer using the heating time of a first discharge device for obtaining a'first timing interval and using the discharge timing of a resistor-condenser network which'is charged during said first time interval to obtain a second timed interval.

These and other objects of the present invention will be understood upon a consideration of the accompanying specification, claims and drawing of which:

The singl figure shows diagrammatically the timing apparatus as it may be employed to actuate an appropriate electrical circuit according to a predetermined sequence.

Referrin now to the single figure, the numeral Iii represents the signal light for indicating when a first time interval has expired in the timing apparatus; The numeral H represents a further indicating lamp which is used to indicate the expiration of a second timed interval of the timing apparatus. The timing apparatus is located within the housing indicated generally by the numeral l2. The timing apparatus located within the housing 12 may be seen to comprise a pair of electron discharge devices 15 and 20. The discharge device I5 comprises an anode IS, a control electrode 11 connected to a cathode l8 and a filamentary type heater 19 which is adapted to heat the cathode [8 to be electron emissive. The discharge device 20 comprises an anode 2|, a control electrode 22, a cathode 23 and a filament type heater 24 which is adapted to heat the oathode 23 to be electron emissive.

Supplying an energizing voltage for the discharge devices 15 and 20 is a transformer 25 having a primary winding 26 which is connected to a suitable source of power and a pair of secondary windings 27 and 28. Located in the energizing circuit for the discharge device 15 is a control relay as having a relay winding 3| and a pair of switch blades 32 and 33. The switch blade 32 is normally biased into engagement with an associated switch contact 34, by means not shown, and the switch blade 33 is normally biased out of engagement with an associated contact 35, by means not shown. A suitable by-pass condenser 36 is connected across relay winding 3| and functions in the normal manner to filter the direct current flOWillg in the anode circuit of the discharge device 15.

Located on the input of the discharge device 20 is a resistor-condenser timing network 40 which comprises an adjustable resistance device 4| and a timing condenser 42. Located in the anode circuit of the device 23 is a relay 45 having a relay winding 43 and a switch blade 4'! which is normally biased by means not shown out of engagement with an associated contact 48. A suitable by-pass condenser 49 is connected across the relay winding 45.

In considering the operation of the present in-- vention, it will first be assumed that the main control switch M is in the open position. When the switch I4 is in the open position the apparatus will be deenergized and the control signal lights l and II will not haveany operating voltages applied thereto bythe relaysi'of the timing device l2. apparatus in operation it is necessary to first close the main control switch I4 Which will complete the energizing circuit to the filament heaters of the discharge devices I 5 and 20. This energizing voltage may be traced from the upper terminal of secondary winding 28 through conductor 60, filament heater I 9, conductor, filament heater 24, conductor 63, control switch l4 and conductor 34back to the lower terminal of secondary 28; With this last traced circuit completed the filament heaters I9 and 24 will begin to heat their associated cathodes l8 and 23.

After a predetermined time the cathodes I8 and 23 will be heated sufiiciently so that they will tend to become electron emissive, When the cathode 13 becomes sufiiciently heated to become electron emissive, there will be a current flow through the discharge device Eon the half cycle of the alternating voltage when the anode is positive with respect to the cathode. This current flow may be traced from the upper terminal of secondary 21 through relay winding 3|, conductor 65, anode |6, cathode |8, and conductors BSand ,6! baclr to the lower terminal of secondary 27. The further circuit may also be traced through the resistor 4| of the timing network 48 and this circuit may betraced from the upper terminal of secondary 21'through conductor 88, resistor 4|, conductor '69, switch contact- 34, switch blade 32, conductor 65, anode l6, cathode l8, and-conductors 88 and B'Iback to the lower terminal of secondary 27. With the current flowing in the last traced circuit through resistor 4|, there will be a voltage drop across the resistor4| and this voltage drop will be such that the upper terminal of the resistor 4| is positive with respectto the lower terminal.

Inasmuch as the condenser 42 is efiectively connected in parallel with the resistor 4| by conductors l8 and II it will be seen that the condenser 42 will assume a polarity which is directly proportional to the voltage .drop across the resistor 4|. This drop is also directly proportional to the voltage drop across the relay winding 3| since the condenser 42 is also essentially connected in parallel with the relay winding 3| by way of conductors 1D and 68 on one terminal and by way of conductors 69 and 1|, switchcontact 34 and-switch blade 32 to winding 3| on the other terminal of. condenser42. The voltage built up across the condenser 42 will be of such a polarity as to tend to maintain the discharge device 28- nonconducting. This will be seen since the upper terminal of condenser 42 is connected directly .to the cathode 23 bymeans of a conductor 12 When it is desired to start the creases with the continued heating of the cathode by the heater I9, eventually the current flow through the discharge device will become sufficient to energize the relay 38. The time that it takes for the relay 30 to become energized after the main control switch I4 has been operated may be, for example, about 15 seconds.

When the relay 30 becomes energized the switch blade 32 moves out of engagement with switch contact 34 and the switch blade 33 moves into engagement with switch contact 35. When switch blade 33 engages contact 35 an energizing circuit will be completed to the indicating light in and the associated control circuit and this circuit may be traced from the input line 88 through conductor 82, indicating light l8, conductor-s 83 and 84, switch blade 33, switch contact 35, and conductor 85 back to the other input power line 8|. With the operation of the lamp I3, the apparatus will indicate the expiration of the first'timing interval in the timing sequence of the apparatus. 7 3 r When the switch blade 32 moves out of engagement with switch contact 34, thecharging circuit for the condenser 42 is interrupted. With the interruption of this charging circuit, the condenser 42 will discharge through the resistor 4|. This discharge circuit may be traced from the upper terminal of condenser 42 through conductor 70, resistor 4|, conductor back to the lower terminal of condenser 42. Asthe condenser 42 discharges the control electrode 22 of discharge device 20 becomes biased less negative with respect to the cathode 23 and after a predetermined time the charge on the condenser 42 will have reached a point where current will pass through the discharge device 20 and this current flow will energize the relay 45.

The current new circuit for the discharge device 20 may be traced from the lower terminal of secondary 21 through conductors 81 and 86, relay'winding 46, anode 2|, cathode 23,- and conductors T2, 10, and 88 back to the upper terminal of secondary 21. When current is flowing in the last traced circuit, the relay 45 will become energized and the switch blade- 41 will move into engagement with switch contact 48. When this occurs, the indicating light M will indicate the expiration of the second time interval. It will be seen that this second time interval will be completed' a certain time interval following the first time interval-which will be dependent upon the time constants of the timing network 40. The energizing circuit for the indicating light I I may be traced from the input power line through conductor 81, light conductor 88, conductor 89, switch contact 48, switch blade 41, and conductor 9! back to the other input power line 8|.

The apparatus is. now in the operating positionwith both of the timing control relays'30 and 45 in their energized positions and their respective indicating lamps l0 and H indicating the expiration of the first two time intervals. The'apparatus will remain in its energized position until such time as the main control switch |4 is moved to the open position.

When the main control switch I4 is moved to the open position it is desired that the control relays remain in the energized position for a predetermined time following the opening of the main control switch. As soon as the main control switch, I4 is moved to the open position the energizing circuit to the filament heaters l8 and 24 will be broken. With the opening of the energizing circuit to the filament heaters the heaters will begin to cool as willrthev associated cathodes I 8 and 23. Due to the heat storage capacity of the oath.- odes i8 and 2.3 the cathodes will remain electron emissive for a predetermined period which may be, for example, approximately 13 seconds. As long as thesecathodes remain electron emissive there will be current flowing through the discharge devices l5 and and the relays and will remain in the energized position. .As soon as the electron emission of the associated cathodes drops below the value necessary to maintain the relays energized and the condensers in parallel therewith are discharged, the relays will drop out and the apparatus will return'to the position shown upon the drawing. When-the relays 3B .and 45 are moved to their deenergized position, the energizing circuits for the indicating lamps I0 and U will be open. Upon the subsequent closing of the main control switch 14. the apparatus will go through its operating cycle in th manner described above. Obviously, the operation, or the relays 130 and 45 may be :used tocontrol any desired apparatus in the sequence described above.

From the foregoing it will be seen that the present invention provides an apparatus for obtaining a plurality of timed sequences by utilizing the heating timing of an indirectly heated cathode, the discharge timing and the resistorcondenser network which was charged during the heating period of the cathode and the cooling periodof the cathode. While a specific embodiment of the invention has been shown, it will be obvious to those skilled in the art that f many modifications may be made well within the scope of the invention and therefore I intend the invention to b limited solely by the scope of the appended claims.

1 through said electron emissive timer reaching a predetermined value following actuation of said switch and being maintained energized under the l control of said switch, a second timer having a second responsive means and said time delay network connected in circuit therewith, and means including said time delay network for maintaining said second timer inefiective for a timed period following energization of said first responsive means.

2. A timing device comprising, a thermal electron emissive timer having an energizing circuit which is completed by means including an actuating switch, a first current responsive means and an electrical time delay network connected in a series-parallel current flow circuit with said thermal emissive timer, said first responsive means being energized upon the current fiow through said electron emissive timer reaching a predetermined value a timed period following actuation of said switch, and upon energization to disconnect said network from said thermal emissive timer, said first responsive means being maintained energized under the control of said switch,-a second timer having a second responsive means and said. time delay network: connected in circuit therewith, .and means including said network for maintaining said second timer ineffective for a timed period following energization of said first responsive means.

3.1L timing apparatus, comprising in combination. a. first electron discharge device having an anode, and a cathode heated to be electron emissive by a filament heater, first responsive means connected in a current flow circuit with said discharge device and adapted to be enere gized thereby when the current .flow there-. through reaches a predetermined value, switch means when actuated connected to complete an energizing circuit to said filament heater so that after a predetermined time said. responsive :means will be energized and maintained energized under the control of said switchmeans, a time delay network initially connected by switch contacts :01- said, first responsive means to said discharge de vice, said network being disconnected by said switch contacts from said device when said re-i sponsive means becomes energized, a secondrdischarge device having further current responsive means in circuit therewith, and means including said network for maintaining said second discharge device ineffiective for a predetermined length of time following energization of said first responsive means.

4. A timing apparatus, comprising in combination, a first electron discharge device having an anode and a cathode heated to be electron emissive by a, filament heater, first responsive means connected in a current flow. circuit with said discharge device and adapted to be energized thereby when the current flow there through reaches a predetermined value; switch means when actuated connected to complete an energizing circuit to said filament heater so that after a predetermined time said responsive means will be energized and maintained energized under the control of said switch means, a resistor condenser delay network initially connected by switch contacts of said first responsive means to said discharge device, said network being dis-- connected by said contacts from said device when said responsive means becomes energized, a second discharge device having further current responsive means in circuit therewith, and means including said network .for maintaining said second discharge device ineffective iorja predetermined length of time dependent upon the. time constant .of said network uponsaidfii'st responsive means becoming energized.

5. A timing apparatus, comprising in combination, a first electron discharge device having an anode and a cathode heated to be electron emissive by a filament heater, a second electron dis charge device having an anode, control electrode and a cathode heated to be electron emissive by a filament heater, means connecting said fila-. ments through control switch means to a source of power so that a predetermined time following actuation of said switch the associated cathodes, will become electron emissive, first current responsive means connected in a current flow circuit with said first discharge device adapted to be energized upon the associated cathode becoming sufiiciently electron emissive and to be main-, tained energized under the control of said control switch means, electrical timing controlmeans interconnecting said first discharge device in biasing relation with said second device so that upon the cathodes of said devices becoming .cur-;

rent emissive the electron'fiow in said first device actingon said control means will maintain said device nonconducting, means including said first responsive means upon becoming energized disconnecting said control means from said first discharge device,'said control means adapted to maintain said second discharge device nonconducting for a predetermined period following energization of said first responsive means-and second current responsive means connected in circuit with said second device adapted 'to be energized upon said device becoming conducting and to be maintained energized. under theicone trol ofsaid control switch means. 7

6. A timing apparatus} comprising in. combination, 'a'firstelectron discharge device having an anodeand a cathode heated to be electron emissive: by a filament heater, a second electron discharge" device havingan anode, control electrode and a cathode heated to be electron emissive by a filament heater, means connecting said filaments through control switch means to a source of power so that apredetermined time following actuation of said switch the associated cathodesiwill become electron emissive, firstcurrent responsive means connected in a current flow circuitlwith said first discharge device adapted to be energized upon the associated cathode becoming sufiiciently electron emissive and to be maintained energized under the control of said control switch means, a resistor-capacitor'network connected in said current flow circuitinterconnecting. said first discharge device in biasing relation with said second dischargc'device so that upon'the cathodes of said'devices becoming CH1? rentemissive the electron fiow in said first device acting on said network will maintain-said device nonconducting, means including said first responsive means upon becoming energized for disconnecting saidnetwork from said first discharge device, said network when disconnected maintaining said second device nonconducting for a predetermined period, andsecond current-responsive means connected in circuit with said second device adapted to be energized upon said device becoming conducting and to be maintained energized under the control of said controlfswitch means. I v

, "7. A timing apparatus, comprising in combina-' tion, first and second electron discharge devices each having an anode, a cathode and a filament heater arranged when energized to heat said cathode tobe electron emissive after a timed period, an energizing circuit connectedto each of said heaters including a main control switch, first and second relay means connected in series circuit with each of said devices respectively, means responsive to the current fiow through said first discharge device rendering said first relay means operative a predetermined time fol lowing actuation of said control switch to ener-' gize said heaters, means including an electrical timing circuit means initially connected by said first relay means to the anode of said first discharge-device and to said second discharge device to maintain said second discharge device inoperative for a further timed period following energization of said first relay means, and means including said second discharge device rendering said second relay means operative upon the expiration of said'further timed period, said cathodes remaining electron emissive for a timed period following deenergization of said heaters to maintain both of said relay means operative for an additional period following actuation of .8 sa'id'main control switch to deenergize said heaters'; :2

8. A timing apparatus comprising in combination, first 1 switch means, a first timing means having saidfirst switch means in an energizing circuit therewith, first current responsive means having an-ope'rativeand an inoperative position, means including said first timing means for actuating said first responsivemeans to its operative position a-timed period following'actuation of saidfirst switch means and to maintain said first responsive means in its operative position under the control of said first switch means, a second timing means having an energizing circuit controlled by said first switch means and having -a second current responsive means in circuit therewith, said second current responsive means'having an operative and an inoperative p0sition,-and means including said first respon sive means for rendering said second timing means effective toenergize said second responsive means to its operative position a timedperiod following actuation of said first'responsive means to its operative position and to maintain said second' responsive means in its operative positi'on'unde'r the control of said switch means, said last named means comprising an electrical timing circuit which is initially connected to be charged by said first timing means when said first current responsive means is in its inoperative'position l T Y 9. A timing apparatus comprising in combination, first switchmeans, a" first timing means in cluding an electron discharge device having said first's'witchmeans'in an energizingcircuit therewith, first current responsive means in circuit with said'discharge device, said first current responsive means having an operative and an inoperative position, means including said first timing means for actuating said first-responsive means toits operative" position a timed period following actuation of said-first switch means and to maintain said first responsive means in its operative position under the control of said first switch means, a second timing means having a second current responsive means in circuit therewith and having an energizing circuit controlled by saidfirst switch means, and means including said first'responsive means for rendering said second timing means effective to QIIET', gize said secondresponsive means a timed period following actuation of said first responsive means to its-operative positionandto maintain said.

second responsive means energized under {thecontrol of said first switch means, said last named means comprising a resistor-capacitor timing network which is initially connected to be charged by said discharge device of said first timing means when said first current responsive means is in its inoperative posi tion. I V

10. A timing apparatus comprising in combination, a first switch means, a first timing means including an electron dischargesdevice having said first switchmeans in an energizing circuit therewith, first currentresponsive means in 011' ing a second current responsive means in circuit therewith, said second timing means having an energizing circuit controlled by said first switch means, and means including said first responsive means for rendering said second timing means effective to energize said second responsive means a timed period following actuation of said first responsive means to its operative position and to maintain said second responsive means energized under the control of said first switch means, said last named means comprising an electrical timing circuit which is initially connected to be charged by said first named discharge device when said first current responsive means is in its inoperative position.

11. A timing apparatus, comprising in combination, a thermal electron emissive timer adapted to be energized by means including an actuating switch, first responsive means in circuit with said timer adapted to be energized when the electron emission of said timer reaches a predetermined value and to be maintained energized under the control of the actuating switch, and second timing means connected to said first responsive means and having a second responsive means in circuit therewith, said second timing means adapted to be energized by said means including the actuating switch, said second timing means energizing said second responsive means a timed period following energization of said first responsive means and maintaining said second responsive means energized under the control of the actuating switch, said second timing means comprising an electrical timing network which is initially connected by said first responsive means to be charged by said thermal electron emissive timer when said first responsive means is not energized.

12. A timing apparatus, comprising in combination, a thermal electron emissive timer having an energizing circuit therefore which is adapted to be completed by means including an actuating switch, first responsive means in circuit with said timer adapted to be energized when the electron emission of said timer reaches a predetermined value and to be maintained energized under the control of the actuating switch, second timing means connected to said first responsive means when said first responsive means is not energized, said second timing means comprising an electrical time delay network initially connected by said first responsive means to be charged by said thermal electron emissive timer when said first responsive means is not energized, and means including said network rendering said second timing means effective a 10 timed period following energization of said first responsive means and maintaining said second timing means effective under the control of said actuating switch.

13. A timing apparatus, comprising in combination, a thermal electron emissive timer having an energizing circuit therefore which is adapted to be completed by means including an actuating switch, first responsive means in circuit with said timer having an energized and a deenergized condition and adapted to be energized when the electron emission of said timer reaches a predetermined value and to be maintained energized under the control of the actuating switch, second timing means connected to said first responsive means when said first responsive means is deenergized, said second timing means comprising an electrical time delay network connected by said first responsive means when in the deenergized condition to said electron emissive timer to be charged to a voltage proportional to the thermal emission required to energize said first responsive means, and means including said network rendering said second timing means effective a timed period following energization of said first responsive means.

RICHARD S. FEIGAL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,516,646 Rosely Nov. 25, 1924 1,751,374 Waltemath Mar. 18, 1930 1,914,215 Price June 13, 1933 1,974,123 Stogoif Sept. 11, 1934 2,073,701 Lazzarini Mar. 16, 1937 2,090,531 Hardin Aug. 17, 1937 2,143,501 Snyder Jan. 10, 1939 2,207,055 Goodling July 9, 1940 2,256,117 Keeley Sept. 16, 1941 2,299,501 Schneider Oct. 20, 1942 2,339,750 Bartholy Jan. 25, 1944 2,414,443 Busch et al Jan. 21, 1947 2,429,186 Johnson Oct. 4, 1947 2,433,254 Aiken Dec. 23, 1947 2,458,283 McCreary Jan. 4, 1949 2,463,318 Schneider Mar. 1, 1949 2,467,008 Brown Apr. 12, 1949 2,566,309 Erode Sept. 4, 1951 OTHER REFERENCES Review of Scientific Instruments, November 1939, vol. 10, pages 323-324. 

